During fast charging, the rate that energy can be taken in and the number of times a cell can be fast charged is greatly determined by the amount of heat generated and removed during the charging operation. The primary thermal management material used today to spread this heat is aluminum. Unfortunately, aluminum is thick, dense, and is a poor conductor of heat. When aluminum is used for fast charging, the battery pack becomes too large and heavy to be practical for EV use. Graphite enables fast charging and increased energy density, while making the battery pack smaller and lighter.

 

Flexible Graphite Cooling Fins are a new technology to spread heat in pouch-cell battery modules. These fins are half the thickness and a third of the weight of equivalent aluminum fins, the current heat spreading technology. These fins now make it possible to both continuously fast charge the batteries and extend the driving range.